Various medical devices, including stents, stent grafts, and venous filters, are deployed within the vasculature of a patient using delivery systems. Some of the medical devices are self-expanding, in a radial direction, and require restriction from radial expansion prior to deployment. According to some coaxial delivery systems, an outer sheath maintains a restricted position of the self-expanding medical device during advancement of the medical device to a deployment site. Once the medical device, which is supported on an inner catheter, is positioned at or near the deployment site, the sheath is removed, or refracted, to permit radial expansion of the self-expanding medical device. The retraction of the sheath is typically facilitated through manipulation of a handle positioned at a proximal end of the deployment system.
The interior spaces of the medical device delivery system are typically flushed prior to use to remove air from the medical device delivery system and, thus, reduce the risk of introducing air into the vascular system. With particular regard to coaxial medical device delivery systems, a separate flushing port is typically provided for each lumen, or space, of the coaxial medical device delivery system. For example, the inner catheter defines a first space having a first flushing port, and the outer sheath defines a second space having a second flushing port. To flush the medical device delivery system, a clinician must flush each of the separate spaces independently using a respective one of the respective flushing ports. This conventional arrangement typically utilizes one or more o-ring seals to seal the interior spaces from proximal leakage of the flushing liquid from the medical device delivery system.
U.S. Pat. No. 8,057,529 to Cox et al. teaches a flushing system for a stent delivery system that includes openings extending through an inner tubular member of the stent delivery system. The openings effectively open a passageway from a guide wire lumen defined by the inner tubular member to an annular space formed between the inner tubular member and an outer tubular member of the stent delivery system. A mandrel is placed in the guide wire lumen at a distal tip assembly of the stent delivery system to block the flow of a sterile flushing fluid through the distal tip. Although the Cox et al. reference discusses the potential use of a single flushing port, sealing of the spaces defined by the inner and outer tubular members is not discussed. Further, there remains a continuing need for efficient and effective medical device delivery systems, including improved flushing systems therefor.
The present disclosure is directed toward one or more of the problems or issues set forth above.